A novel power stability drive system of semiconductor Laser Diode for high-precision measurement

Abstract

In view of the strict requirements of the current high-precision measurement system for stable output power of the semiconductor LD (Laser Diode), a semiconductor LD stable power drive and multi-closed-loop control system are proposed after analyzing the semiconductor laser’s P–I (Power–Current) characteristics and temperature characteristics. The system uses a microcontroller as the core control unit and realizes the stable power output control of the semiconductor laser by controlling the current, power and temperature parameters. In this system, first, the control structure model of the controlled object has been designed. Second, a controllable closed-loop constant current feedback drive circuit has been designed and a high-precision controllable constant current drive circuit of the semiconductor laser has been obtained. Furthermore, the control circuit has been designed based on the neural PI (Proportional-Integral) control model and realizes the short-term stable power output of the semiconductor LD. Finally, a closed-loop temperature control system is designed to ensure that the operating temperature of the semiconductor laser is relatively stable and a long-term stable power output is obtained. By designing the hardware and software of the control system and conducting long-term experiments in the laboratory, we found that the system can guarantee the output power within 1 W of PD (Proportional-Differential) LD, and its long-term power stability can reach 1%. This system has a certain reference significance in using semiconductor lasers for high-quality detection when there are stringent requirements for power.

Design of High Precision Semiconductor Laser System

“…The stability of the temperature is also directly related to the stability of the laser output power. Therefore, the control of the temperature in the laser is a very important part of the whole system [5]. Temperature control system is usually a time-varying, nonlinear, complex large inertia system with pure delay, which is usually controlled by PID control algorithm, but the traditional PID method cannot meet the control requirements of high-precision temperature control system, in order to make PID parameters adapt to the control requirements of different temperature sections and obtain more accurate temperature control effect.…”

Sensing strategy based on random slot semiconductor laser

“…Semiconductor lasers are used in a wide range of applications, such as sensors [1], space laser communications [2], precision measurements [3], pumped solid-state lasers [4], and fiber lasers [5]. There are many types of grating semiconductor lasers, including first-order distributed feedback (DFB) lasers [6,7], first-order distributed Bragg reflector (DBR) lasers [8,9], surface-emitting DFB semiconductor lasers [10,11], surface high-order grating lasers [12,13], and so on.…”

Design and Stability Analysis of a Digital Automatic Power Control Based on a PI Controller for Laser Drivers

“…The emission spectrum undergoes displacements on the order of tenths of nm (wavelengths) by each Celsius degree of variation in the laser operating temperature [8][9][10]. In addition, decreases in the quantum efficiency modify the relation between the laser supply current with the emitted optical power [8,9,11]. These changes can impact the performance of the specific applications.…”

“…The optical power stabilization methods can be classified as internal and external control systems. The internal control modifies the internal parameters of the laser operation, such as the forward current or supplies current, temperature, and cavity, among others [11][12][13]. On the other hand, the external control systems require external modulators, such as opto-acoustic or electro-optics modulators in the laser outlet, to modify or stabilize the optical parameters of the laser.…”

“…The implementation of a proportional-integral (PI) controller in a laser power driver, which operates with a fixed optical power output at a stable temperature, is described in [11]. However, there are no general design rules for the controller (proportional gain K p and integral gain K p /T i ).…”